Images (videos) captured through optical systems often include deterioration caused by aberration of the optical system. The deterioration includes, for example, defocusing caused by chromatic aberration of the optical system in respective colors in the captured image and distortion of the captured image caused by distortion aberration of the optical system.
Japanese Patent Laid-Open No. 2006-135805 has disclosed an apparatus which calculates an amount of chromatic aberration on an image pickup plane to perform image processing (hereinafter referred to as “aberration correction image processing”) for correcting deterioration of a captured image caused by the chromatic aberration.
However, the aberration correction image processing requires a certain amount of time to be performed. Further, it is necessary to newly calculate correction data (hereinafter referred to as “aberration correction data”) used for the aberration correction image processing because a zoom operation of an optical system changes chromatic aberration generated in the optical system. The aberration correction data for an actual zoom position is calculated by interpolation calculation or the like using the aberration correction data (table data) for representative zoom positions prepared in advance. Therefore, the calculation of the aberration correction data requires an amount of time.
The amount of time required for the calculation of the aberration correction data causes a delay from image pickup of an image (hereinafter referred to as “correction target image”) which is a target of the aberration correction image processing until the aberration correction image processing is allowed after the calculation of the aberration correction data. In other words, even if the aberration correction image processing on the correction target image is desired to be started immediately after the image pickup of the correction target image, the aberration correction data cannot be generated in time for the aberration correction image processing. It is possible to generate the aberration correction data in advance by using a zoom position before the image pickup of the correction target image. However, since that aberration correction data is not generated based on a zoom position at the point in time of the image pickup of the correction target image, it is not possible to appropriately perform the aberration correction image processing.